重定向到另一个地址

I have a page (done in CodeIgniter) associated with WordPress. The blog has changed address:

From example.com/wp to example.com/blog

I want to other posts from the old address may appear at a new address, for example.: example.com/blog?p=32

I created a controller:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

require_once LIBRARIES.'functions.inc';

class Wp extends CI_Controller {
    public function index()
    {
        $this->load->helper('url');
        redirect("/blog", "refresh");
    }

    public function _remap($method) {
        Remap($this, $method);
    }
}

But does not work. What could be wrong?